crosvm: use vcpu cgorups for plugin
crosvm: use vcpu cgorups for plugin

BUG=b:228634930
TEST=presubmit --quick

Change-Id: I92f0a025280fca0cdfdf6b2420cbfd213ec0bc08
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3696460
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Auto-Submit: Anton Romanov <7c8c28e1283c1d87f2c3df4d6b5c74b6ae02bcd9@google.com>
Commit-Queue: Dmitry Torokhov <10a8c465cefc9bdd6c925e26964d23c90f1141cc@chromium.org>
Reviewed-by: Dmitry Torokhov <10a8c465cefc9bdd6c925e26964d23c90f1141cc@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm